Bent tube boiler



Patented June 23, 1931 Y Unir-ED STATES PATENT OFFICE VALTER LOCKE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGN OR TO EDGE MOOR IRON COMPANY, OF EDGE MOOR, DELAWARE, A CORPORATION F DELAWARE BENT TUBE BOILER Application filed. April 21,

My invention relates to bent tube boilers of the type in which two upper drums are conn-ected toa lower drum by banks of bent tubes and in which the front upper and lower drums and the tube banks connecting there drums may be said to constitute the steaming element or" the boiler and the rear upper and lower drums and tube banks'connecting them may be said to constitute the water ;y heatin@f element of the boiler. In such boilers the steam spaces of the upperidrums are connected and the steam is drawn from the boilers from the rear upper drum; where, as is'now usually the case, boilers of this type operated at very high pressures, the drums are necessarily made of somewhat restricted diameter and holding capacity and under certain conditions of operation the water level in the upper drums is liable to tall to an undesirably low level. It is also true that in such boilers when working at high duty veryconsiderable bodies of steam are generated in the front tube bank, resulting in a vgreat agitation of the water in the front upper drum and the carrying off by the steam issuing therefrom of considerable quantities of entrained water, as a result of which there is apt to be such agitation in the water levelof the rear upper drum as to malte the ascertainment oi the true water levelin this drum as by a water glass a mat ter vof some diihculty in view of the tact that the water in this drum forms a part of the circulatory system of the water heating ele` ment ot the boiler. The object oi my invention is, in the first place, to provide an ad`r Vditional reservoir of water by which unduly rapid variations of water level in the boiler can be prevented, to provide improved means for separating entrained water from the steam issuing from the front upper drum and for the delivery of comparatively dry steam from the boiler and to provide a qui-escent body of water the level of which will approximately indicatethe true water level and my invention consists in providing in combination with a boiler of the type described a third upper drum located between and approximately at the level of the two upper drums of the boiler proper, the steam 1930. serial No. 445,904.

space of which is connected with that of the two upper drums of the boiler proper and the water space ot which is also connected with the water space of the rear upper drum so that water can flow freely from the intermediate upper drum to the rear upper drum when for any reason the water level in the rear upper drum falls. It is an essential feature of my invention that the intermediate upper drum should be disconnected from the main circulatory system of the boiler so that the water contained' therein shall be free from agitation.

By preference I connect the intermediate upper drum with the lower drum by a row oi' water tubes located in the rear of the steaming section, such tubes functioning, where for any reason there is a rapid fall in the water level of the boiler, to supply water directly to the lower drum as well as to the upper rear drum and thus more promptly to equalize the water level in the steaming section of the boiler. The capacity and location ot this row of water tubes are such as will not under any conditions bring about any considerable circulatory movement of the water in the intermediate drum but preferably, and as far as possible, I protect this row of water tubes from direct contact with the heating gases by bailles and in certain typ-es of baliling I can and do utilize this row of water tubes to support a baille which will protect them from direct Contact with the .gases while at the same time serving to give proper direction to the gases among the water tubes constituting a part ot' the main circulatory system of the boiler.

My invention will perhaps be better understood by describing it in connection with the drawings, which is a longitudinal vertical section through a boiler embodying my improvements and shown as located in a furnace and setting of the usual character.

A indicates the furnace. B the front upper drum; B1 the lower drum; B2 the rear upper drum and B3 the fourth drum, located at approximately the level of' and between the upper drums but entirely unconnected with the tube banks provided 'for the circusteaming elements of the boiler. C represents the bank of bent tubes located at the frontl of the steaming section. C1 the bank of bent tubes located at the rear of the steaming section. C2 and C3 make up the bank of bent tubes provided for the heating ysectien consisting of a group of tubes C2 through which water moves upward from the lower 'drum to the rear upper Vdrum and another group of tubes C3 through which the water moves downward from the rear upper drum to the lower drum. D indicates a header exe tending parallel with and behind lthe rear upper drum and connecting through a row of tubes D1 with the lower drum B1. These tubes through which the feed water is introduced open into a-bon b1 with which box, ,as shown, is also connected the uptake tubes G2.

'E indicates a baiiiefor directing the fur-nace gases .through the steaming section in connection with a rear battle indicated at B1, located at the rear of the tube bank C1. rhe lower end of this baiile connects as indicated at E2 with an upwardly. extending baflie E3 lying in front of the tube bank connecting the rear upper and lower drums. The gases are further directed in upfiow through this tube bank by baffles indicated at E4 and E5. F indicates the outlet passage for gases. G indicates steam tubes connecting the steam space of the ydrum B with the steam space o'f the drum B3, and G1 the steam' tubes connecting the steam space of the drum B3 with the rear drum B2. H indicates water tubes connecting the bottom of the drums B3 and B2.

' it indicates a row of water tubes leading from the lfourth drum B3 to the lower drum B1. As shown, these tubes are located behind the baflie El so that onl their lowerr ends lie inv circulating the direct path of the gases l inthrough the tube system of Vthe boiler.

jdicates a pipe connectionk for drawing oif the water from thev drum B1. d a baiiie located in the drum B3. K a baffle located at the top i' of the drum B3 in frontof the take-olf parsage L. f l

n operation water entering through the header D passes through the tubes D1 to the boi; b1 of the drumeBl, then passes upward from'this box throughthetube group C2 to lthe upper rear drum B2, thence downward through the tubegroup C3 to the lower drum, thence upward along the tubegroup C to the upper front drum "B, thence downward through tube group C1- to the lower drum. Steam from the front upper drum of the steaming section enters the drum B3, the steam pipesV G1 connecting the drum B3 and the drum BL maintaining constant pressure in the drums and the steam being preferably drawn od through the drum B3. In case for anyreason the water levell should fall rapidly in the boiler the reserve of water contained in the drum B3 will flow promptly intothe drum B2, thus preventing any material or dangerous change of Water level. The drum B3 being entirely disconnected with the circulatory system of the boiler, the water maintained in it will be in a state of quiescence, thus enabling the steam entering this drum to shed its entrained water and also enabling the true approximate water levelV of the boiler to be ascertained` with fair accuracy by a gauge attached to the drum B3.V

While l believe the baille system illustrated yand described as peculiarly well adapted for boilers involving my improvement, it will be understoodthat my improved device can be advantageously employed with boilers having different baffle systems.

Having new described my invention, what l claim as new and desire to secure by Letters Patent, is: l

l. A bent tube boiler comprising a steaming section made up of an upper and lower drum` connected by two banks of bent 'tubes and provided with bafiles located between the tube banks'and in the rear of the rear bank to direcu furnace gases upward along. the front bank yand downward along the rear bank, said 'boiler having also a water heating section made up of drum located approximately on the'level of the upper drum of the steaming section and tubes connecting said drum to the lower drum of the steaming section said heating section beingprovided with baffles for vdirecting the gases upward along the tubes, in combinationwith a fourth drum located approximately on'the level of the upper drums aforesaid, said` fourth drum being unconnected with the tube banks forming the maincirculatory system of the steaming and water heating elements of the boiler but having steam conduitsconnecting its steam space with the steam spaces ofthe other two upper drums and water conduits connecting its bottom with the bottom of the rear upper drum acting to'maintain an approximately uniform water level in the Vso connected drums. Y

' 2. A boiler-having thefeatures of claim l havingrin addition to the short water conduits connecting the fourth and rear upper drums a row of y water conduits extending from the bott-om of the fourth vdrum to the lower drum, said row of water conduits lying at the rear of the rear tubebank of thesteam` ing section and separated therefrom bythe baflie by which the gases vare directed downward along said bank.

wALTEa'FLooKE. 

